First, mount your dos hard disk partition as a Linux subdirectory.
For example, you could create a directory in Linux such as /dos (mkdir
-m 755 /dos) and add a line like

/dev/hda1 /dos msdos umask=022

to your /etc/fstab. (In this example, the hard disk is mounted
read-only. You may want to mount it read/write by replacing "022"
with "000" and using the -m 777 option with mkdir). Now mount
/dos. Now you can add a line like

lredir d: linux\fs/dos

to the AUTOEXEC.BAT file in your hdimage (see the comments on LREDIR
below). On a multi-user system you may want to use

lredir d: linux\fs\${home}

where "home" is the name of an environmental variable that contains
the location of the dos directory (/dos in this example)(95/8/11).

---------------------

Tim Bird (Tim_R_Bird@Novell.COM) states that LREDIR users should
be careful when they use LREDIR in the autoexec, because COMMAND.COM
will continue parsing the autoexec.bat from the redirected drive as
the same file offset where it left off in the autoexec.bat on the
physical drive. For this reason, it is safest to have the
autoexec.bat on the redirected drive and the physical drive
(diskimage) be the same(95/8/11).

Use the recent mtools, version 3.0 at the time of writing. With a
line in /etc/mtools.conf like

drive g: file="/var/lib/dosemu/hdimage" Offset=8832

you can use the mtools on the hdimage, like "mdir g:". "mcopy
g:/config.emu /tmp" copies the config.emu file from the hdimage to
/tmp/config.emu. You can edit it there and copy it back. Use a drive
letter you find sensible. "G:" is only an example(07/2/9).

At this time, compressed drives cannot be accessed via the
redirector (lredir or emufs) on a standard kernel. There is a patch
for the kernel to mount compressed files under the name "dmsdosfs".
Find it on sunsite.unc.edu and its mirrors

If your dos partition is already mounted with write access and you try
to run dosemu with partition or whole disk access, dosemu will print a
warning message and abort. This prevents DOS and Linux from making
independent writes to your disk and trashing the data on your dos
partition(95/8/11).

---------------------

If LILO is installed, the above will not work. However...

Thomas Mockridge (thomas@aztec.co.za) reported (94/8/5) that

To boot dosemu with LILO and Stacker 4.0 I did a little work around...

1. dd the MBR to a file. (or norton utility, etc., first 512 bytes)

2. Boot dos (from full boot not emu), do a fdisk /mbr, make your dos
partition active with (dos) fdisk.

3. Copy the new MBR to a file.

4. Replace the original MBR

5. Copy the second MBR to /var/lib/dosemu/partition.hda? (Whichever is
your dos partition)